The value of effective T2 (T2*) relaxation time in monitoring changes in liver arterial blood supply after partial hepatectomy was investigated using a rat model. Ten rats received a 30% hepatectomy, and the other ten received a 70% hepatectomy. Before and after the surgery, all animals underwent T2* mapping at multiple time points. Liver T2* relaxation times were measured and compared between different groups at each time point. The results indicated that T2* relaxation time can be used to monitor changes in liver arterial blood supply after partial hepatectomy.